This question's answer depends on the actual language of the contract coupled with your state's contract law. That being said, you may want to consult with a local attorney about these items. However, in the abstract, if there are grounds for termination based on personal issues, such as illneess, there would likely have to be express language in the agreement for that possibility.
I hope this helps.
Disclaimer: This answer is for informational purposes only and does not constitute general or specific legal advice, nor create an attorney client relationship.